This invention relates to a computer system and, more particularly, relates to a computer system run under a disk operation system (DOS).
In a further respect, the invention relates to a DOS computer system which effectively extends the DOS main memory capacity without the addition of supplemental random access memory (RAM) to the DOS main memory.
In another respect, the invention relates to a DOS computer system which increases, without the addition of supplemental RAM, the number of available files handles in the system.
In still another respect, the invention relates to a computer system which is run under DOS and which enables application programs to be transferred from secondary hard disk memory to RAM on an as needed basis and enables active application programs in RAM to be placed in suspension in virtual memory for instantaneous recall to RAM to become an active application program and be executed from the point at which the application program was suspended for transfer to virtual memory.
In yet a further respect the invention relates to a computer system which is run under a disk operating system and which enables application programs to transfer control and send messages to other application programs.
A personal computer or microcomputer typically uses a disk operating system (DOS). DOS is a set of commands or programs that the computer uses to provide a uniform interface between the computer hardware and application programs in the computer. DOS permits the application programs to communicate with the computer hardware. DOS is a relatively primitive software which does not allow application programs to, while execution of the programs is in process, be temporarily suspended for instant recall. One reason DOS does not permit the suspension of in process application programs is the limited storage space provided in RAM for active application programs. If a user wishes to interrupt the execution of an application program in RAM and to begin execution of another application program, the user often must return the active program to secondary disk memory and transfer the other new application program from secondary memory to RAM to be executed. When execution of the new application program is completed and the user wishes to complete execution of the original application program, the DOS resident program directory must be searched to locate and return the original application to RAM to become an active progam to complete execution of the original program.
Accordingly, it would be highly desirable to provide an improved computer system which is run under a disk operating system and which permits an active application program to be temporarily suspended and removed from RAM to secondary hard disk memory in a manner which permits instant recall of the suspended application program to RAM.
Therefore, it is a principal object of the invention to provide an improved computer system which is run under a disk operating system (DOS).
A further object of the invention is to provide an improved microcomputer system which is run under DOS and which enables an active application program to be temporarily suspended from RAM for subsequent instant recall to RAM to complete execution of the application program, the temporary suspension of the application program permitting RAM to be utilized for execution of another active application program.
Another object of the invention is to provide an improved computer system which runs under DOS and which enables application programs to send messages and directly transfer control to other application programs.
Still a further object of the invention is to provide an improved computer system which runs under DOS and which increases the number of file handles which can be utilized in conjunction with DOS to track files utilized during operation of the computer system.
Yet another object of the instant invention is to provide an improved computer system which is run under DOS and which effectively extends the RAM capacity by utilizing a plurality of discrete application programs which each performs one primary function and deals with generally one kind of data.
These and other further and more specific objects and advantages of the invention will be apparent to those skilled in the art from the following detailed description thereof, taken in conjunction with the drawings.